Linearly-actuated magnetocaloric heat pump

ABSTRACT

A heat pump includes a magnet assembly which creates a magnetic field, and a regenerator housing which includes a body defining a plurality of chambers, each of the plurality of chambers extending along a transverse direction orthogonal to the vertical direction. The heat pump further includes a plurality of stages, each of the plurality of stages including a magnetocaloric material disposed within one of the plurality of chambers and extending along the transverse direction between a first end and a second end.

FIELD OF THE INVENTION

The subject matter of the present disclosure relates generally to a heatpump system that uses magnetocaloric materials to exchange heat with acirculating heat transfer fluid.

BACKGROUND OF THE INVENTION

Conventional refrigeration technology typically utilizes a heat pumpthat relies on compression and expansion of a fluid refrigerant toreceive and reject heat in a cyclic manner so as to effect a desiredtemperature change or i.e. transfer heat energy from one location toanother. This cycle can be used to provide e.g., for the receiving ofheat from a refrigeration compartment and the rejecting of such heat tothe environment or a location that is external to the compartment. Otherapplications include air conditioning of residential or commercialstructures. A variety of different fluid refrigerants have beendeveloped that can be used with the heat pump in such systems.

While improvements have been made to such heat pump systems that rely onthe compression of fluid refrigerant, at best such can still onlyoperate at about 45 percent or less of the maximum theoretical Carnotcycle efficiency. Also, some fluid refrigerants have been discontinueddue to environmental concerns. The range of ambient temperatures overwhich certain refrigerant-based systems can operate may be impracticalfor certain locations. Other challenges with heat pumps that use a fluidrefrigerant exist as well.

Magnetocaloric materials (MCMs)—i.e. materials that exhibit themagnetocaloric effect—provide a potential alternative to fluidrefrigerants for heat pump applications. In general, the magneticmoments of an MCM will become more ordered under an increasing,externally applied magnetic field and cause the MCM to generate heat.Conversely, decreasing the externally applied magnetic field will allowthe magnetic moments of the MCM to become more disordered and allow theMCM to absorb heat. Some MCMs exhibit the opposite behavior—i.e.generating heat when the magnetic field is removed (which are sometimesreferred to as para-magnetocaloric material but both types are referredto collectively herein as magnetocaloric material or MCM). Thetheoretical Carnot cycle efficiency of a refrigeration cycle based on anMCM can be significantly higher than for a comparable refrigerationcycle based on a fluid refrigerant. As such, a heat pump system that caneffectively use an MCM would be useful.

Challenges exist to the practical and cost competitive use of an MCM,however. In addition to the development of suitable MCMs, equipment thatcan attractively utilize an MCM is still needed. Currently proposedequipment may require relatively large and expensive magnets, may beimpractical for use in e.g., appliance refrigeration, and may nototherwise operate with enough efficiency to justify capital cost.

Additionally, as stated above, the ambient conditions under which a heatpump may be needed can vary substantially. For example, for arefrigerator appliance placed in a garage or located in a non-airconditioned space, ambient temperatures can range from below freezing toover 90° F. Some MCMs are capable of accepting and generating heat onlywithin a much narrower temperature range than presented by such ambientconditions.

Accordingly, a heat pump system that can address certain challenges suchas those identified above would be useful. Such a heat pump system thatcan also be used in e.g., a refrigerator appliance would also be useful.

BRIEF DESCRIPTION OF THE INVENTION

Additional aspects and advantages of the invention will be set forth inpart in the following description, or may be apparent from thedescription, or may be learned through practice of the invention.

In accordance with one embodiment, a heat pump is provided. The heatpump includes a magnet assembly, the magnet assembly creating a magneticfield. The heat pump further includes a regenerator housing, theregenerator housing including a body defining a plurality of chambers,each of the plurality of chambers extending along a transverse directionorthogonal to the vertical direction. The heat pump further includes aplurality of stages, each of the plurality of stages including amagnetocaloric material disposed within one of the plurality of chambersand extending along the transverse direction between a first end and asecond end.

In accordance with another embodiment, the present disclosure isdirected to a heat pump system. The heat pump system includes a coldside heat exchanger configured for heat removal from a first localenvironment, and a hot side heat exchanger configured for heat deliveryto a second local environment. The heat pump system further includes afirst pump for circulating a working fluid between the cold side heatexchanger and the hot side heat exchanger, and a second pump forcirculating a working fluid between the cold side heat exchanger and thehot side heat exchanger. The heat pump system further includes a heatpump in fluid communication with the cold side heat exchanger, the hotside heat exchanger, the first pump and the second pump. The heat pumpincludes a magnet assembly, the magnet assembly creating a magneticfield. The heat pump further includes a regenerator housing, theregenerator housing including a body defining a plurality of chambers,each of the plurality of chambers extending along a transverse directionorthogonal to the vertical direction. The heat pump further includes aplurality of stages, each of the plurality of stages including amagnetocaloric material disposed within one of the plurality of chambersand extending along the transverse direction between a first end and asecond end.

In some embodiments, one of the regenerator housing or the magnetassembly is movable relative to the other of the regenerator housing orthe magnet assembly along a longitudinal direction orthogonal to thevertical direction and the transverse direction.

In some embodiments, in a first position along the longitudinaldirection the regenerator housing is positioned such that a first stageof the plurality of stages is within the magnetic field and a secondstage of the plurality of stages is out of the magnetic field. In asecond position along the longitudinal direction the regenerator housingis positioned such that the first stage of the plurality of stages isout of the magnetic field and the second stage of the plurality ofstages is within the magnetic field.

In some embodiments, the heat pump further includes a cam connected toone of the regenerator housing or the magnet assembly. The one of theregenerator housing or the magnet assembly is movable relative to theother of the regenerator housing or the magnet assembly along alongitudinal direction orthogonal to the vertical direction and thetransverse direction due to rotation of the cam.

In some embodiments, the plurality of chambers of the regeneratorhousing include a plurality of first chambers and at least one secondchamber, the first and second chambers disposed in an alternatingarrangement along the longitudinal direction. An insulative material isdisposed within the at least one of the plurality of second chambers.

In some embodiments, the magnet assembly includes a first magnet and asecond magnet, the first magnet and the second magnet spaced apart alonga vertical direction such that a gap is defined between the first magnetand the second magnet and a magnetic field is created in the gap.

In some embodiments, the support frame includes an upper frame memberand a lower frame member spaced apart along the vertical direction fromthe upper frame member, the support frame further including anadjustable intermediate member disposed between the upper frame memberand the lower frame member, wherein the first magnet is connected to theupper frame member and the second magnet is connected to the lower framemember, and wherein adjustment of the adjustable intermediate memberadjusts a length of the gap.

In some embodiments, a width along the longitudinal direction of thefirst magnet and a width along the longitudinal direction of the secondmagnet are greater than or equal to widths along the longitudinaldirection of each of the plurality of stages

In some embodiments, the heat pump further comprises a bearing assembly,wherein the regenerator housing is a component of the bearing assembly.

In some embodiments, each of the plurality of stages further defines afirst aperture at the first end and a second aperture at the second end.Working fluid is flowable from a stage though the second aperture and tothe stage through the first aperture when the stage is in the magneticfield. Working fluid is flowable from a stage though the first apertureand to the stage through the second aperture when the stage is out ofthe magnetic field.

In some embodiments, the heat pump further includes a plurality offlexible lines in fluid communication with each of the plurality ofstages.

In some embodiments, the heat pump further includes a plurality of linesin fluid communication with each of the plurality of stages, each of theplurality of lines comprising an inner sleeve and an outer sleeve, theinner sleeve at least partially disposed within the outer sleeve. One ofthe inner sleeve or the outer sleeve of each of the plurality of linesis movable relative to the other of the inner sleeve or the outer sleeveof that line during movement of the one of the regenerator housing orthe magnet assembly.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 is a refrigerator appliance in accordance with one embodiment ofthe present disclosure;

FIG. 2 is a schematic illustration of a heat pump system positioned inan exemplary refrigerator with a machinery compartment and arefrigerated compartment in accordance with one embodiment of thepresent disclosure;

FIG. 3 is a schematic illustration of a heat pump system, with a firststage of MCM within a magnetic field and a second stage of MCM out of amagnetic field, in accordance with one embodiment of the presentdisclosure;

FIG. 4 is a schematic illustration of a heat pump system, with a firststage of MCM out of a magnetic field and a second stage of MCM within amagnetic field, in accordance with one embodiment of the presentdisclosure;

FIG. 5 is a front view of components of a heat pump, with first stagesof MCM within magnetic fields and second stages of MCM out of magneticfields, in accordance with one embodiment of the present disclosure;

FIG. 6 is a front view of components of a heat pump, with first stagesof MCM out of magnetic fields and second stages of MCM within magneticfields, in accordance with one embodiment of the present disclosure;

FIG. 7 is a top view of a regenerator housing and MCM stages disposedtherein in accordance with one embodiment of the present disclosure;

FIG. 8 is a top view of components of a heat pump in accordance with oneembodiment of the present disclosure;

FIG. 9 is a chart illustrating movement of a regenerator housing andassociated MCM stages in accordance with one embodiment of the presentdisclosure;

FIG. 10 is a chart illustrating operation of pumps to actively flowworking fluid in accordance with one embodiment of the presentdisclosure;

FIG. 11 is a schematic diagram illustrating various positions andmovements there-between of MCM stages in accordance with one embodimentof the present disclosure.

FIG. 12 is a schematic perspective view of MCM stages and associatedseals in accordance with one embodiment of the present disclosure;

FIG. 13 is a top view of MCM stages in a first position in accordancewith one embodiment of the present disclosure;

FIG. 14 is a top view of the MCM stages of FIG. 13 between a firstposition and a second position;

FIG. 15 is a top view of the MCM stages of FIG. 14 in a second position;

FIG. 16 is a top view of a regenerator housing and MCM stages disposedtherein in accordance with one embodiment of the present disclosure;

FIG. 17 is a side view of the regenerator housing and MCM stages of FIG.16;

FIG. 18 is a front view of components of a heat pump, with first stagesof MCM out of magnetic fields and second stages of MCM within magneticfields, in accordance with one embodiment of the present disclosure;

FIG. 19 is a front view of components of a heat pump, including aregenerator housing, magnet assembly and bearing assembly, in accordancewith one embodiment of the present disclosure;

FIG. 20 is a side view of components of a heat pump, including aregenerator housing, magnet assembly and cam, in accordance with oneembodiment of the present disclosure; and

FIG. 21 is a top view of components of a heat pump, including aregenerator housing and MCM stages disposed therein as well as linesextending therefrom.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

Referring now to FIG. 1, an exemplary embodiment of a refrigeratorappliance 10 is depicted as an upright refrigerator having a cabinet orcasing 12 that defines a number of internal storage compartments orchilled chambers. In particular, refrigerator appliance 10 includesupper fresh-food compartments 14 having doors 16 and lower freezercompartment 18 having upper drawer 20 and lower drawer 22. The drawers20, 22 are “pull-out” type drawers in that they can be manually movedinto and out of the freezer compartment 18 on suitable slide mechanisms.Refrigerator 10 is provided by way of example only. Other configurationsfor a refrigerator appliance may be used as well including applianceswith only freezer compartments, only chilled compartments, or othercombinations thereof different from that shown in FIG. 1. In addition,the heat pump and heat pump system of the present disclosure is notlimited to appliances and may be used in other applications as well suchas e.g., air-conditioning, electronics cooling devices, and others.Thus, it should be understood that while the use of a heat pump and heatpump system to provide cooling within a refrigerator is provided by wayof example herein, the present disclosure may also be used to providefor heating applications as well.

FIG. 2 is a schematic view of another exemplary embodiment of arefrigerator appliance 10 including a refrigeration compartment 30 and amachinery compartment 40. In particular, machinery compartment 30includes a heat pump system 52 having a first or cold side heatexchanger 32 positioned in the refrigeration compartment 30 for theremoval of heat therefrom. A heat transfer fluid such as e.g., anaqueous solution, flowing within first heat exchanger 32 receives heatfrom the refrigeration compartment 30 thereby cooling its contents. Afan 38 may be used to provide for a flow of air across first heatexchanger 32 to improve the rate of heat transfer from the refrigerationcompartment 30.

The heat transfer fluid flows out of first heat exchanger 32 by line 44to heat pump 100. As will be further described herein, the heat transferfluid receives additional heat from magnetocaloric material (MCM) inheat pump 100 and carries this heat by line 48 to pump 42 and then tosecond or hot side heat exchanger 34. Heat is released to theenvironment, machinery compartment 40, and/or other location external torefrigeration compartment 30 using second heat exchanger 34. A fan 36may be used to create a flow of air across second heat exchanger 34 andthereby improve the rate of heat transfer to the environment. Pump 42connected into line 48 causes the heat transfer fluid to recirculate inheat pump system 52. Motor 28 is in mechanical communication with heatpump 100 as will further described.

From second heat exchanger 34 the heat transfer fluid returns by line 50to heat pump 100 where, as will be further described below, the heattransfer fluid loses heat to the MCM in heat pump 100. The now colderheat transfer fluid flows by line 46 to first heat exchanger 32 toreceive heat from refrigeration compartment 30 and repeat the cycle asjust described.

Heat pump system 52 is provided by way of example only. Otherconfigurations of heat pump system 52 may be used as well. For example,lines 44, 46, 48, and 50 provide fluid communication between the variouscomponents of the heat pump system 52 but other heat transfer fluidrecirculation loops with different lines and connections may also beemployed. For example, pump 42 can also be positioned at other locationsor on other lines in system 52. Still other configurations of heat pumpsystem 52 may be used as well.

FIGS. 3 through 21 illustrate exemplary heat pumps 100 and componentsthereof, and the use of such heat pumps 100 with heat pump system 52, inaccordance with embodiments of the present disclosure. Components of theheat pump 100 may be oriented relative to a coordinate system for theheat pump 100, which may include a vertical direction V, a transversedirection T, and a longitudinal direction L all of which may be mutuallyorthogonal to each other.

Heat pump 100 includes one or more magnet assemblies 110, each of whichcreates a magnetic field M. For example, a magnetic field M may begenerated by a single magnet, or by multiple magnets.

In exemplary embodiments as illustrated, a first magnet 112 and a secondmagnet 114 may be provided, and the magnetic field M may be generatedbetween the magnets. The magnets 112, 114 may, for example, haveopposite magnetic polarities such that they either attract or repel eachother.

The magnets 112, 114 of a magnet assembly 110 may be spaced apart fromeach other, such as along a vertical direction V. A gap 116 may thus bedefined between the first magnet 112 and the second magnet 114, such asalong the vertical direction V.

The heat pump 100 may further include a support frame 120 which supportsthe magnet assembl(ies) 110. A magnet assembly 110 may be connected tothe support frame 120. For example, each magnet 112, 114 of the magnetassembly 110 may be connected to the support frame 120. Such connectionin exemplary embodiments is a fixed connection via a suitable adhesive,mechanical fasteners, and/or a suitable connecting technique such aswelding, brazing, etc. The support assembly 120 may, for example,support the magnets 112, 114 in position such that the gap 114 isdefined between the magnets 112, 114.

As illustrated, support frame 120 is an open-style frame, such thatinterior portions of the support frame 120 are accessible from exteriorto the support frame 120 (i.e. in the longitudinal and transversedirections L, T) and components of the heat pump 100 can be traversedfrom interior to the support frame 120 to exterior to the support frame120 and vice-versa. For example, support frame 120 may define one ormore interior spaces 122. Multiple interior spaces 122, as shown, may bepartitioned from each other by frame members or other components of thesupport frame 120. An interior space 122 may be contiguous withassociated magnets 112, 114 (i.e. magnet assembly 110) and gap 116, suchas along the longitudinal direction L. Support frame 120 mayadditionally define one or more exterior spaces 124, each of whichincludes the exterior environment proximate the support frame 120.Specifically, an exterior space 124 may be contiguous with associatedmagnets 112, 114 (i.e. magnet assembly 110) and gap 116, such as alongthe longitudinal direction L. An associated interior space 122 andexterior space 124 may be disposed on opposing sides of associatedmagnets 112, 114 (i.e. magnet assembly 110) and gap 116, such as alongthe longitudinal direction L.

As illustrated in FIGS. 5, 6 and 18, the support frame 120 and framemembers and other components thereof may include and form one or moreC-shaped portions. A C-shaped portion may, for example, define aninterior space 122 and associated gap 116, and may further define anassociated exterior space 124 as shown.

In exemplary embodiments as illustrated, a support frame 120 may supporttwo magnet assemblies 110, and may define an interior space 122, gap116, and exterior space 124 associated with each of the two magnetassemblies 110. Alternatively, however, a support frame 120 may supportonly a single magnet assembly 110 or three or more magnet assemblies110.

Various frame members may be utilized to form the support frame 120. Forexample, in some embodiments, an upper frame member 126 and a lowerframe member 127 may be provided. The lower frame member 127 may bespaced apart from the upper frame member 126 along the vertical axis V.The first magnet(s) 112 may be connected to the upper frame member 126,and the second magnet(s) 114 may be connected to the lower frame member127. In exemplary embodiments, the upper frame member 126 and lowerframe member 127 may be formed from materials which have relatively highmagnetic permeability, such as iron.

In some embodiments, as illustrated in FIGS. 5 and 6, a support frame120 may further include an intermediate frame member 128. Theintermediate frame member 128 may be disposed and extend between andconnect the upper frame member 126 and lower frame member 127, and mayin some embodiments be integrally formed with the upper and lower framemembers 126, 127. As shown, multiple interior spaces 122 may bepartitioned from each other by intermediate frame member 128. In someembodiments, the intermediate frame member 128 may be formed frommaterials which have relatively high magnetic permeability, such asiron. In other embodiments, the intermediate frame member 128 may beformed from materials which have relatively lower magnetic permeabilitythan those of the upper and lower frame members 126, 127. Accordingly,such materials, termed magnetically shielding materials herein, mayfacilitate direction of magnetic flux paths only through the upper andlower frame members 126, 127 and magnet assemblies 110, advantageouslyreducing losses in magnetic strength, etc.

In embodiments wherein an intermediate frame member 128 is utilized,lengths (i.e. maximum lengths) 117 of the gaps 116 may be fixed andnon-adjustable.

In other embodiments, as illustrated in FIG. 18, the lengths 117 mayadvantageously be adjustable. For example, a support frame 120 mayfurther include an adjustable intermediate member 129. The adjustableintermediate member 129 may be disposed and extend between and connectthe upper frame member 126 and lower frame member 127. As shown,multiple interior spaces 122 may be partitioned from each other byadjustable intermediate member 129. In some embodiments, the adjustableintermediate member 129 may be formed from materials which haverelatively high magnetic permeability, such as iron. In otherembodiments, the adjustable intermediate member 129 may be formed frommaterials which have relatively lower magnetic permeability than thoseof the upper and lower frame members 126, 127. Accordingly, suchmaterials, termed magnetically shielding materials herein, mayfacilitate direction of magnetic flux paths only through the upper andlower frame members 126, 127 and magnet assemblies 110, advantageouslyreducing losses in magnetic strength, etc.

Adjustment of the adjustable intermediate member 129 may adjust thelength(s) 117 of the gap(s) 116, increasing or decreasing the gap(s) 116as desired. Accordingly, the gap(s) 116 may be adjusted to achieveoptimal magnetic fields M for operation of heat pumps 100 in accordancewith the present disclosure. In exemplary embodiments as shown, theadjustable intermediate member 129 may be or include a screw jack.Alternatively, other suitable adjustable mechanisms may be utilized,such as pulley systems, other mechanical gear-based systems,electronically actuated systems, etc.

Referring again to FIGS. 3 through 21, a heat pump 100 may furtherinclude a plurality of stages, each of which includes a magnetocaloricmaterial (MCM). In exemplary embodiments, such MCM stages may beprovided in pairs, each of which may for example include a first stage130 and a second stage 132. Each stage 130, 132 may include one or moredifferent types of MCM. Further, the MCM(s) provided in each stage 130,132 may be the same or may be different.

When provided in heat pump 100, each stage 130, 132 may extend, such asalong the transverse direction T, between a first end 134 and a secondend 136. As discussed herein, working fluid (also referred to herein asheat transfer fluid or fluid refrigerant) may flow into each stage 130,132 and from each stage 130, 132 through the first end 134 and secondend 136. Accordingly, working fluid flowing through a stage 130, 132during operation of heat pump 100 flows generally along the transversedirection T.

Stages 130, 132, such as each pair of stages 130, 132, may be disposedwithin regenerator housings 140. The regenerator housing 140 along withthe stages 130, 132 and optional insulative materials 138 maycollectively be referred to as a regenerator assembly. A housing 140includes a body 142 which defines a plurality of chambers 144, each ofwhich extends along the transverse direction T between opposing ends ofthe chamber 144. The chambers 144 of a regenerator housing 140 may thusbe arranged in a linear array along the longitudinal direction L, asshown. Each stage 130, 132, such as of a pair of stages 130, 132, may bedisposed within one of the plurality of chambers 144 of a regeneratorhousing 140. Accordingly, these stages 130, 132 may be disposed in alinear array along the longitudinal direction L.

As illustrated, in exemplary embodiments, each regenerator housing 140may include a pair of stages 130, 132. Alternatively, three, four ormore stages 130, 132 may be provided in a regenerator housing 140.

In some embodiments, as illustrated in FIGS. 5 through 8 and 18, eachchamber 144 of the regenerator housing 140 may include a stage 130, 132therein, and/or neighboring chambers 144 may include stages 130, 132.Alternatively, as illustrated in FIGS. 16 and 17, chambers 144 which areneighbors to those chambers 144 which include a stage 130, 132 mayinclude an insulative material 138. The insulative material mayadvantageously reduce heat transfer between the stage 130, 132 andambient, and between the various stages 130, 132 themselves, thusincreasing the efficiency of the heat pump 100 generally.

For example, as illustrated in FIGS. 16 and 17, the plurality ofchambers 144 may include a plurality of first chambers 144′ and at leastone, such as in exemplary embodiments a plurality of, second chamber144″. The first and second chambers 144′, 144″ may be disposed in analternating arrangement along the longitudinal direction L. Accordingly,neighboring chambers 144 alternate, with first chambers 144′ next tosecond chambers 144″ and second chambers 144″ next to first chambers144′ along the longitudinal direction L. A first chamber 144′ may not benext to another first chamber 144′ along the longitudinal direction L,and a second chamber 144″ may not be next to another second chamber 144″along the longitudinal direction.

The MCM stages 130, 132 may be disposed in the first chambers 144′ (andnot in the second chambers 144″). An insulative material 138 (which isnot an MCM) may be disposed within the second chambers 144″. In someembodiments, the insulative material 138 may simply be air. In otherembodiments, the insulative material 138 may be a foam, i.e. a closedcell foam such as a closed cell urethane foam or closed cell expandedpolystyrene foam.

In exemplary embodiments, a width 145″ (i.e. a maximum width) along thelongitudinal direction L of each second chamber 144″ may be greater thanor equal to one-half of a height 146 (i.e. a maximum height) along thevertical direction V of each first chamber 144′. In some embodiments, awidth 145″ may be between one-half of a height 146 and a width 145′(i.e. a maximum width) along the longitudinal direction L of each firstchamber 144′. In other embodiments, a width 145″ may be greater than awidth 145′. Such widths 145″ relative to the widths 145′ and heights 146may advantageously increase the insulating effects of the insulativematerial 138.

As illustrated in FIGS. 5, 6 and 18, each stage 130, 132 may define awidth 131, 133 along the longitudinal direction L, and each magnet 112,114 may define a width 113, 115. The widths 113, 115 of the magnets 112,114 may advantageously be sized such that the magnetic field M issufficient to energize the stages 130, 132 and thus facilitate optimaloperation of the heat pump 100. For example, in exemplary embodiments,the widths 113, 115 may be greater than or equal to the widths 131, 133.In particularly advantageous embodiments, the widths 113, 115 may begreater than the widths 131, 133. Notably, the widths 113, 115 may insome embodiments be limited, and may for example, be less than two timesthe widths 131, 133. For example, the widths 113, 115 may be between onetime and two times the widths 131, 133.

Notably, in exemplary embodiments, widths 113 and 115 may beapproximately equal, and widths 131 and 133 may be approximately equal.

The regenerator housing(s) 140 (and associated stages 130, 132) andmagnet assembly(s) 110 may be movable relative to each other, such asalong the longitudinal direction L. In exemplary embodiments as shown,for example, each regenerator housing 140 (and associated stages 130,132) is movable relative to an associated magnet assembly 110, such asalong the longitudinal direction L. Alternatively, however, each magnetassembly 110 is movable relative to the associated regenerator housing140 (and associated stages 130, 132), such as along the longitudinaldirection L.

Such relative movement (i.e. of a regenerator housing 140 in exemplaryembodiments) causes movement each stage 130, 132 into the magnetic fieldM and out of the magnetic field M. As discussed herein, movement of astage 130, 132 into the magnetic field M may cause the magnetic momentsof the material to orient and the MCM to heat (or alternatively cool) aspart of the magnetocaloric effect. When a stage 130, 132 is out of themagnetic field M, the MCM may thus cool (or alternatively heat) due todisorder of the magnetic moments of the material.

For example, a regenerator housing 140 (or an associated magnet assembly110) may be movable along the longitudinal direction L between a firstposition and a second position. In the first position (as illustratedfor example in FIGS. 3 and 5), the regenerator housing 140 may bepositioned such that a first stage 130 disposed within the regeneratorhousing 140 is within the magnetic field M and a second stage 132disposed within the regenerator housing 140 is out of the magnetic fieldM. Notably, being out of the magnetic field M means that the secondstage 132 is generally or substantially uninfluenced by the magnets andresulting magnetic field M. Accordingly, the MCM of the stage as a wholemay not be actively heating (or cooling) as it would if within themagnetic field M (and instead may be actively or passively cooling (orheating) due to such removal of the magnetic field M). In the secondposition (as illustrated for example in FIGS. 4 and 6), the regeneratorhousing 140 may be positioned such that the first stage 130 disposedwithin the regenerator housing 140 is out of the magnetic field M andthe second stage 132 disposed within the regenerator housing 140 iswithin the magnetic field M.

The regenerator housing 140 (or an associated magnet assembly 110) ismovable along the longitudinal direction L between the first positionand the second position. Such movement along the longitudinal directionfrom the first position to the second position may be referred to hereinas a first transition, while movement along the longitudinal directionfrom the second position to the first position may be referred to hereinas a second transition.

Referring to FIGS. 8, 9 and 20, movement of a regenerator housing 140(or an associated magnet assembly 110) may be caused by operation ofmotor 26. The motor 26 may be in mechanical communication with theregenerator housing 140 (or magnet assembly 110) and configured formoving the regenerator housing 140 (or magnet assembly 110) along thelongitudinal direction L (i.e. between the first position and secondposition). For example, a shaft 150 of the motor 28 may be connected toa cam; i.e. a regenerator cam. The cam may be connected to theregenerator housing 140 (or associated magnet assembly 110), such thatrelative movement of the regenerator housing 140 and associated magnetassembly 110 is caused by and due to rotation of the cam. The cam may,as shown, be rotational about the longitudinal direction L (see FIGS. 8and 9) or the transverse direction T (see FIG. 20).

For example, in some embodiments as illustrated in FIGS. 8 and 9, thecam may be a cam cylinder 152. The cam cylinder 152 may be rotationalabout the longitudinal direction L. A cam groove 154 may be defined inthe cam cylinder 152, and a follower tab 148 of the regenerator housing120 may extend into the cam groove 154. Rotation of the motor 28 maycause rotation of the cam cylinder 152. The cam groove 154 may bedefined in a particularly desired cam profile such that, when the camcylinder 152 rotates, the tab 148 moves along the longitudinal directionL between the first position and second position due to the pattern ofthe cam groove 154 and in the cam profile, in turn causing such movementof the regenerator housing 120.

In other embodiments, as illustrated in FIG. 20, the cam may be a camwheel 156. The cam wheel 156 may be rotational about the transversedirection T. A follower rod 158 may be pivotally and movably coupled toand between the cam wheel 156 and the regenerator housing 120. Rotationof the motor 28 may cause rotation of the cam wheel 156. The outerprofile of the cam wheel 156 may be defined in a particularly desiredcam profile such that, when the cam wheel 156 rotates, the follower rod158 moves along the longitudinal direction L between the first positionand second position due to the pattern of the outer profile of the camwheel 156 and in the cam profile, in turn causing such movement of theregenerator housing 120.

FIG. 9 illustrates one embodiment of a regenerator cam profile whichincludes a first position, first transition, second position, and secondtransition. Notably, in exemplary embodiments the period during which aregenerator housing 140 (or an associated magnet assembly 110) isdwelling in the first position and/or second position may be longer thanthe period during which the regenerator housing 140 (or an associatedmagnet assembly 110) is moving in the first transition and/or secondtransition. Accordingly, the cam profile defined by the cam defines thefirst position, the second position, the first transition, and thesecond transition. In exemplary embodiments, the cam profile causes theone of the regenerator housing or the magnet assembly to dwell in thefirst position and the second position for periods of time longer thantime periods in the first transition and second transition.

Referring now to FIG. 19, in some embodiments the movement of aregenerator housing 140 and magnet assembly 110 relative to each other(i.e. the movement of the regenerator housing 140 relative to the magnetassembly 110 in exemplary embodiments) may advantageously be facilitatedvia use of a bearing assembly 220. The bearing assembly 220 may supportthe regenerator housing 140 and magnet assembly 110 relative to eachother, maintaining tight tolerances for the gap 116 and causing smooth,efficient movement during operation of the heat pump 100. Notably, toprovide such advantages, the regenerator housing 140 may be a componentof the bearing assembly 220.

Bearing assembly 220 may, for example, include one or more outer races222 and a plurality of bearings 224. The bearings 224 may, for example,be ball bearings, wheel bearings, slide bearings, or other suitablebearing components. The regenerator housing 140, such as the outersurface(s) of the body 142 thereof, may serve as the inner race(s) ofthe bearing assembly. Accordingly, bearings 224 may be disposed betweenthe regenerator housing 140, such as the outer surface(s) of the body142 thereof, and the outer races 222 along the vertical direction V.

The bearing assembly 220 may further be connected to the magnet assembly110. For example, each outer race 222 may be connected to the firstmagnet 112 or the second magnet 114. One or more outer races 222 may beconnected to the first magnet 112 and to the second magnet 114. Forexample, as shown, one outer race 222 connected to the first magnet 112and the second magnet 114 may be disposed in the interior space 122,which another outer race 222 connected to the first magnet 112 and thesecond magnet 114 may be disposed in the exterior space 124.

Accordingly, during movement of the regenerator housing 140 between thefirst position and the second position, the regenerator housing 140 maymove relative to the outer races 222 and along the bearings 224, thusfacilitating improved movement of the regenerator housing 140.

Referring again to FIG. 2, in some embodiments, lines 44, 46, 48, 50 mayfacilitate the flow of working fluid between heat exchangers 32, 34 andheat pump 100. Referring now to FIGS. 3, 4, 7 and 12 through 15, inexemplary embodiments such various lines may facilitate the flow ofworking fluid between heat exchangers 32, 34 and the stages 130, 132 ofthe heat pump 100. Working fluid may flow to and from each stage 130,132 through various apertures defined in each stage. The aperturesgenerally define the locations of working fluid flow to or from eachstage. In some embodiments as illustrated in FIGS. 3, 4 and 7, multipleapertures (i.e. two apertures) may be defined in the first end 134 andthe second end 136 of each stage 130, 132. For example, each stage 130,132 may define a cold side inlet 162, a cold side outlet 164, a hot sideinlet 166 and a hot side outlet 168. The cold side inlet 162 and coldside outlet 164 may be defined in each stage 130, 132 at the first end134 of the stage 130, 132, and the hot side inlet 166 and hot sideoutlet 168 may be defined in each stage 130, 132 at the second end 136of the stage 130, 132. The inlets and outlets may provide fluidcommunication for the working fluid to flow into and out of each stage130, 132, and from or to the heat exchangers 32, 34. For example, a line44 may extend between cold side heat exchanger 32 and cold side inlet162, such that working fluid from heat exchanger 32 flows through line44 to cold side inlet 162. A line 46 may extend between cold side outlet164 and cold side heat exchanger 32, such that working fluid from coldside outlet 164 flows through line 46 to heat exchanger 32. A line 50may extend between hot side heat exchanger 34 and hot side inlet 166,such that working fluid from heat exchanger 34 flows through line 50 tohot side inlet 166. A line 48 may extend between hot side outlet 168 andhot side heat exchanger 34, such that working fluid from hot side outlet168 flows through line 48 to heat exchanger 34.

When a regenerator housing 140 (and associated stages 130, 132) is in afirst position, a first stage 130 may be within the magnetic field and asecond stage 132 may be out of the magnetic field. Accordingly, workingfluid in the first stage 130 may be heated (or cooled) due to themagnetocaloric effect, while working fluid in the second stage 132 maybe cooled (or heated) due to the lack of magnetocaloric effect.Additionally, when a stage 130, 132 is in the first position or secondposition, working fluid may be actively flowed to the heat exchangers32, 34, such as through inlets and outlets of the various stages 130,132. Working fluid may be generally constant within the stages 130, 132during the first and second transitions.

One or more pumps 170, 172 (each of which may be a pump 42 as discussedherein) may be operable to facilitate such active flow of working fluidwhen the stages are in the first position or second position. Inexemplary embodiments, each pump is or includes a reciprocating piston.For example, a single pump assembly may include two reciprocatingpistons. For example, a first pump 170 (which may be or include apiston) may operate to flow working fluid when the stages 130, 132 arein the first position (such that stage 130 is within the magnetic fieldM and stage 132 is out of the magnetic field M), while a second pump 172(which may be or include a piston) may operate to flow working fluidwhen the stages 130, 132 are in the second position (such that stage 132is within the magnetic field M and stage 130 is out of the magneticfield M). Operation of a pump 170, 172 may cause active flow of workingfluid through the stages 130, 132, heat exchangers 32, 34, and system 52generally. Each pump 170, 172 may be in fluid communication with thestages 130, 132 and heat exchangers 32, 34, such as on various linesbetween stages 130, 132 and heat exchangers 32, 34. In exemplaryembodiments as shown, the pumps 170, 172 may be on “hot side” linesbetween the stages 130, 132 and heat exchanger 34 (i.e. on lines 48).Alternatively, the pumps 170, 172 may be on “cold side” lines betweenthe stages 130, 132 and heat exchanger 32 (i.e. on lines 44). Referringbriefly to FIG. 10, operation of the pumps 170, 172 relative to movementof a regenerator housing 140 and associated stages 130, 132 through acam profile is illustrated. First pump 170 may operate when the stagesare in the first position, and second pump 172 may operate when thestages are in the second position.

Working fluid may be flowable from a stage 130, 132 through the hot sideoutlet 168 and to the stage 130, 132 through the cold side inlet 162when the stage is within the magnetic field M. Working fluid may beflowable from a stage 130, 132 through the cold side outlet 164 and tothe stage through the hot side inlet 166 during movement of the stage130, 132 when the stage is out of the magnetic field M. Accordingly, andreferring now to FIGS. 3 and 4, a first flow path 180 and a second flowpath 182 may be defined. Each flow path 180 may include flow through afirst stage 130 and second stage 132, as well as flow through cold sideheat exchanger 32 and hot side heat exchanger 34. The flow of workingfluid may occur either along the first flow path 180 or the second flowpath 182, depending on the positioning of the first and second stages130, 132.

FIG. 3 illustrates a first flow path 180, which may be utilized in thefirst position. In the first position, the first stage 130 is within themagnetic field M, and the second stage 132 is out of the magnetic fieldM. Activation and operation of pump 170 may facilitate active workingfluid flow through the first flow path 180. As shown, working fluid mayflow from cold side heat exchanger 32 through line 44 and cold sideinlet 162 of first stage 130 to the first stage 130, from the firststage 130 through hot side outlet 168 and line 48 of the first stage 130to the hot side heat exchanger 34, from hot side heat exchanger 34through line 50 and hot side inlet 166 of the second stage 132 to thesecond stage 132, and from the second stage 132 through cold side outlet164 and line 46 of the second stage 132 to the cold side heat exchanger32.

FIG. 4 illustrates a second flow path 182, which may be utilized duringthe second position. In the second position, the second stage 132 iswithin the magnetic field M, and the first stage 130 is out of themagnetic field M. Activation and operation of pump 172 may facilitateactive working fluid flow through the second flow path 182. As shown,working fluid may flow from cold side heat exchanger 32 through line 44and cold side inlet 162 of second stage 132 to the second stage 132,from the second stage 132 through hot side outlet 168 and line 48 of thesecond stage 132 to the hot side heat exchanger 34, from hot side heatexchanger 34 through line 50 and hot side inlet 166 of the first stage130 to the first stage 130, and from the first stage 130 through coldside outlet 164 and line 46 of the first stage 130 to the cold side heatexchanger 32.

Notably, check valves 190 may in some embodiments be provided on thevarious lines 44, 46, 48, 50 to prevent backflow there-through. Thecheck valves 190, in combination with differential pressures duringoperation of the heat pump 100, may thus generally prevent flow throughthe improper flow path when working fluid is being actively flowedthrough one of the flow paths 190, 192.

Referring now to FIGS. 12 through 15, in alternative embodiments only asingle aperture may be defined in the first end 134 and the second end136 of each stage 130, 132. As illustrated, a first aperture 202 isdefined in the first end 134, and a second aperture 204 is defined inthe second end 136. The working fluid is flowable (i.e. via operation ofthe pumps 170, 172 as discussed herein) both to and from the stages 130,132 through the first and second apertures 202, 204 thereof. Forexample, working fluid may be flowable from a stage 130, 132 though thesecond aperture 204 and to the stage 130, 132 through the first aperture202 when the stage 130, 132 is in the magnetic field M. Working fluidmay be flowable from a stage 130, 132 though the first aperture 202 andto the stage 130, 132 through the second aperture 204 when the stage130, 132 is out of the magnetic field M.

The flow of working fluid to or from a stage 130, 132 may flow into orfrom a line 44, 46, 48, 50, and this flow may then continue through thestage and/or to a heat exchanger 32, 34 as described herein. Tofacilitate such flow to or from the lines 44, 46, 48, 50, seals may beprovided adjacent and in contact with the first ends 134 and second ends136 of the stages 130, 132. The stages 130, 132 may be movable betweenthe first position and second position relative to the stages 130, 132.As shown, one or more first seals 206 may be positioned adjacent to(along the transverse direction T) and in contact with the first ends136, and one or more second seals 208 may be positioned adjacent to(along the transverse direction T) and in contact with the second ends138. In exemplary embodiments, the seals 206, 208 may be formed frompolytetrafluoroethylene or another suitable material to facilitate atight seal with the stages 130, 132 while having low friction andallowing movement of the stages 130, 132 between the first position andsecond position.

Each seal 206 may include and define a plurality of ports through whichworking fluid may be selectively flowed to/from lines 44, 46, 48, 50.When a first aperture 202 is aligned with a port in the first seal 206,working fluid may flow to or from the stage 130, 132 through the firstaperture 202 and port. When a second aperture 204 is aligned with a portin the second seal 208, working fluid may flow to or from the stage 130,132 through the second aperture 204 and port. Specifically, in exemplaryembodiments as illustrated, the first aperture 202 of a stage 130, 132may be aligned with a port of the first seal 206 and the second aperture204 of the stage 130, 132 is aligned with a port of the second seal 208when the stage 130, 132 is in the first position or the second position.Notably, the ports with which the apertures 202, 204 are aligned in thefirst position in exemplary embodiments are different from the portswith which the apertures 202, 204 are aligned in the second position.Further, the first aperture 202 of the stage 130, 132 is not alignedwith any port of the first seal 206 and the second aperture 204 of thestage 130, 132 is not aligned with any port of the second seal 208 whenthe stage 130, 132 is moving between the first position and the secondposition (i.e. in the first transition or second transition).

For example, a first seal 206 may include and define a cold side inletport 212 and a cold side outlet port 214 for one or more of the stages130, 132. The second seal 208 may include and define a hot side inletport 216 and a hot side outlet port 218 for one or more stages 130,132.The inlet ports and outlet ports may provide fluid communication for theworking fluid to flow into and out of each stage 130, 132, and from orto the heat exchangers 32, 34. For example, a line 44 may extend betweencold side heat exchanger 32 and cold side inlet port 212, such thatworking fluid from heat exchanger 32 flows through line 44 to cold sideinlet 212. A line 46 may extend between cold side outlet port 214 andcold side heat exchanger 32, such that working fluid from cold sideoutlet port 214 flows through line 46 to heat exchanger 32. A line 50may extend between hot side heat exchanger 34 and hot side inlet port216, such that working fluid from heat exchanger 34 flows through line50 to hot side inlet port 216. A line 48 may extend between hot sideoutlet port 218 and hot side heat exchanger 34, such that working fluidfrom hot side outlet port 218 flows through line 48 to heat exchanger34.

Working fluid may be flowable from the second aperture 204 of a stage130, 132 through the hot side outlet port 218 (and thus to line 48), andto the first aperture 202 of the stage 130, 132 through the cold sideinlet port 212 (and thus from line 44) when the stage 130, 132 is in themagnetic field M (and in the first or second position). Accordingly, andas illustrated in FIGS. 12 and 13, the first aperture 202 may be alignedwith cold side inlet port 212 and the second aperture 204 may be alignedwith the hot side outlet port 218 along the longitudinal axis L. Workingfluid may be flowable to the second aperture 204 of a stage 130, 132through the hot side inlet port 216 (and thus from line 50), and fromthe first aperture 202 of the stage 130, 132 through the cold sideoutlet port 214 (and thus to line 46) when the stage 130, 132 is out ofthe magnetic field M (and in the first or second position). Accordingly,and as illustrated in FIGS. 12 and 15, the first aperture 202 may bealigned with cold side outlet port 214 and the second aperture 204 maybe aligned with the hot side inlet port 216 along the longitudinal axisL. When the stages 130, 132 are moving between the first and secondposition in the first transition or second transition, as illustrated inFIG. 14, the first apertures 202 and second apertures 204 may be alignedwith the surfaces of the respective seals 206, 208, and not aligned withany ports, such that no flow occurs to or from the stages 130, 132.

As discussed, lines 44, 46, 48, 50 may be in fluid communication witheach of the plurality of stages, either directly or via seals. In someembodiments (such as for example when seals are utilized and the linesmay be generally stationary during heat pump 100 operation), the lines44, 46, 48, 50 may be relatively stiff lines. In other embodiments (suchas for example when the lines 44, 46, 48, 50 are directly connected tothe stages and may thus move during heat pump 100 operation), the lines44, 46, 48, 50 may be flexible lines. In particularly exemplaryembodiments of flexible lines, the lines may be axially flexible andradially stiff, thus facilitating movement during operation of the heatpump 100 while maintaining structural integrity.

For example, the flexible lines 44, 46, 48, 50 may each be formed fromone of a polyurethane, a rubber, or a polyvinyl chloride, or anothersuitable polymer or other material. In exemplary embodiments, the lines44, 46, 48, 50 may further be fiber impregnated, and thus includeembedded fibers, or may be otherwise reinforced. For example, glass,carbon, polymer or other fibers may be utilized, or other polymers suchas polyester may be utilized to reinforce the lines 44, 46, 48, 50.

In some exemplary embodiments, each line 44, 46, 48, 50 may have arelatively small minimum bend radius, such as less than or equal to 2inches, less than or equal to 1.5 inches, less than or equal to 1 inch,less than or equal to 0.5 inches, or between 2 inches and 0.25 inches.

Additionally or alternatively, each line 44, 46, 48, 50 may have arelatively high burst pressure rating, such as greater than or equal to50 pounds per square inch (“PSI”), such as greater than or equal to 100PSI, such as greater than or equal to 250 PSI, such as greater than orequal to 400 PSI, such as between 50 PSI and 500 PSI.

Additionally or alternatively, each line 44, 46, 48, 50 may have arelatively small outer diameter, such as less than or equal to 0.5inches, such as less than or equal to 0.25 inches, such as between 0.5inches and 0.125 inches.

In some embodiments, each line 44, 46, 48, 50 may be a singularcomponent that extends between a heat exchanger and a stage or seal. Inother embodiments, and in particular in embodiments wherein the lines44, 46, 48, 50 are rigid, each line may be formed from multiplecomponents which may be movable relative to each other. Such embodimentsmay be particularly applicable when the lines 44, 46, 48, 50 aredirectly connected to the stages and may thus move during heat pump 100operation. For example, and referring now to FIG. 21, each line 230(which could be a line 44, 46, 48 or 50) may include an inner sleeve 232and an outer sleeve 234. The inner sleeve 232 may be at least partiallydisposed within the outer sleeve 234, and the inner sleeve 232 and outersleeve 234 may be in fluid communication such that working fluid flowsfrom the inner sleeve 232 into the outer sleeve 234 and/or from theouter sleeve 234 to the inner sleeve 232 at the intersectiontherebetween. Further, one of the inner sleeve 232 or outer sleeve 234may be movable relative to the other of the inner sleeve 232 or outersleeve 234. Such movement may occur during operation of the heat pump100, and specifically during movement of the regenerator housing 120 ormagnet assembly 110, such as relative to the other between the firstposition and second position. The use of inner and outer sleeves andsuch relative movement may advantageously allow for the working fluid tobe transmitted between the moving regenerator housing 120 (and stages130, 132 thereof) and stationary heat exchangers 130, 132 in arelatively efficient manner, with high reliability and with little or nofluid dead space during operation.

The relative movement of the inner sleeve 232 or outer sleeve 234 ofeach line 230 in exemplary embodiments is along the longitudinaldirection L. In exemplary embodiments, the inner sleeve 232 of each line230 may be movable relative to the outer sleeve 234, such as along thelongitudinal direction L.

Additionally or alternatively, the inner sleeve 232 of each line 230 maybe connected to one of the plurality of stages 130, 132. Accordingly,working fluid may enter a stage 130, 132 from an associated inner sleeve232 or be exhausted from a stage 130, 132 into an associated innersleeve 232. In these embodiments, the outer sleeve 234 may be connectedto one of the heat exchangers 32, 34. Accordingly, working fluid mayenter a heat exchanger 32, 34 from an associated outer sleeve 234 or beexhausted from a heat exchanger 32, 34 into an associated outer sleeve234. One or more seal members 236 may be provided in each line 230, andmay be disposed between the inner sleeve 232 and the outer sleeve 234 ofthe line 230 to prevent leakage at the intersection of the inner sleeve232 and outer sleeve 234. In exemplary embodiments as shown, the sealmember(s) 236 are O-rings, although other suitable seal members 236 maybe utilized.

FIG. 11 illustrates an exemplary method of the present disclosure usinga schematic representation of associated stages 130, 132 of MCM duringdwelling in and movement between the various positions as discussedherein. With regard to the first stage 130, during step 200, whichcorresponds to the first position, stage 130 is fully within magneticfield M, which causes the magnetic moments of the material to orient andthe MCM to heat as part of the magneto caloric effect. Further, the pump170 is activated to actively flow working fluid in the first flow path180. As indicated by arrow Q_(H-OUT), working fluid in stage 130, nowheated by the MCM, can travel out of the stage 130 and along line 48 tothe second heat exchanger 34. At the same time, and as indicated byarrow Q_(H-IN), working fluid from first heat exchanger 32 flows intostage 130 from line 44. Because working fluid from the first heatexchanger 32 is relatively cooler than the MCM in stage 130, the MCMwill lose heat to the working fluid.

In step 202, stage 130 is moved from the first position to the secondposition in the first transition. During the time in the firsttransition, working fluid dwells in the MCM of stage 130. Morespecifically, the working fluid does not actively flow through stage130.

In step 204, stage 130 is in the second position and thus out ofmagnetic field M. The absence or lessening of the magnetic field is suchthat the magnetic moments of the material become disordered and the MCMabsorbs heat as part of the magnetocaloric effect. Further, the pump 172is activated to actively flow working fluid in the second flow path 182.As indicated by arrow Q_(C-OUT), working fluid in stage 130, now cooledby the MCM, can travel out of stage 130 and along line 46 to the firstheat exchanger 32. At the same time, and as indicated by arrow Q_(C-IN),working fluid from second heat exchanger 34 flows into stage 112 fromline 50 when stage 130 is in the second transition. Because workingfluid from the second heat exchanger 34 is relatively warmer than theMCM in stage 130, the MCM will lose some of its heat to the workingfluid. The working fluid now travels along line 46 to the first heatexchanger 32 to receive heat and cool the refrigeration compartment 30.

In step 206, stage 130 is moved from the second position to the firstposition in the second transition. During the time in the secondtransition, the working fluid dwells in the MCM of stage 130. Morespecifically, the working fluid does not actively flow through stage130.

With regard to the second stage 132, during step 200, which correspondsto the first position, the second stage 132 is out of magnetic field M.The absence or lessening of the magnetic field is such that the magneticmoments of the material become disordered and the MCM absorbs heat aspart of the magnetocaloric effect. Further, the pump 170 is activated toactively flow working fluid in the first flow path 180. As indicated byarrow Q_(C-OUT), working fluid in stage 132, now cooled by the MCM, cantravel out of stage 132 and along line 46 to the first heat exchanger32. At the same time, and as indicated by arrow Q_(C-IN), working fluidfrom second heat exchanger 34 flows into stage 112 from line 50 whenstage 132 is in the second transition. Because working fluid from thesecond heat exchanger 34 is relatively warmer than the MCM in stage 132,the MCM will lose some of its heat to the working fluid. The workingfluid now travels along line 46 to the first heat exchanger 32 toreceive heat and cool the refrigeration compartment 30.

In step 202, stage 132 is moved from the first position to the secondposition in the first transition. During the time in the firsttransition, the working fluid dwells in the MCM of stage 132. Morespecifically, the working fluid does not actively flow through stage132.

In step 204, stage 132 is in the second position and thus fully withinmagnetic field M, which causes the magnetic moments of the material toorient and the MCM to heat as part of the magneto caloric effect.Further, the pump 172 is activated to actively flow working fluid in thesecond flow path 182. As indicated by arrow Q_(H-OUT), working fluid instage 132, now heated by the MCM, can travel out of the stage 132 andalong line 48 to the second heat exchanger 34. At the same time, and asindicated by arrow Q_(H-IN), working fluid from first heat exchanger 32flows into stage 132 from line 44. Because working fluid from the firstheat exchanger 32 is relatively cooler than the MCM in stage 132, theMCM will lose heat to the working fluid.

In step 206, stage 132 is moved from the second position to the firstposition in the second transition. During the time in the secondtransition, working fluid dwells in the MCM of stage 132. Morespecifically, the working fluid does not actively flow through stage132.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

What is claimed is:
 1. A heat pump, comprising: a magnet assembly, themagnet assembly comprising a first magnet and a second magnet, the firstmagnet and the second magnet spaced apart along a vertical directionsuch that a gap is defined between the first magnet and the secondmagnet and a magnetic field is created in the gap; a regeneratorhousing, the regenerator housing comprising a body defining a pluralityof chambers, each of the plurality of chambers extending along atransverse direction orthogonal to the vertical direction; a pluralityof stages, each of the plurality of stages comprising a magnetocaloricmaterial disposed within one of the plurality of chambers and extendingalong the transverse direction between a first end and a second end; anda support frame, the support frame comprising an upper frame member anda lower frame member spaced apart along the vertical direction from theupper frame member, the support frame further comprising an adjustableintermediate member disposed between the upper frame member and thelower frame member, wherein the first magnet is connected to the upperframe member and the second magnet is connected to the lower framemember, and wherein adjustment of the adjustable intermediate memberadjusts a length of the gap.
 2. The heat pump of claim 1, wherein themagnet assembly is a plurality of magnet assemblies, wherein each of thefirst magnets is connected to the upper frame member and each of thesecond magnets is connected to the lower frame member.
 3. The heat pumpof claim 1, wherein the adjustable intermediate member is a screw jack.4. The heat pump of claim 1, further the adjustable intermediate memberis formed from a magnetically shielding material.
 5. The heat pump ofclaim 1, wherein the support frame defines an interior space and anexterior space, the interior space and the exterior space disposed onopposing sides of the magnet assembly along the longitudinal direction.6. The heat pump of claim 1, wherein the support frame comprises aC-shaped portion.
 7. The heat pump of claim 1, wherein one of theregenerator housing or the magnet assembly is movable relative to theother of the regenerator housing or the magnet assembly along alongitudinal direction orthogonal to the vertical direction and thetransverse direction, and wherein in a first position along thelongitudinal direction the regenerator housing is positioned such that afirst stage of the plurality of stages is within the magnetic field anda second stage of the plurality of stages is out of the magnetic field,and wherein in a second position along the longitudinal direction theregenerator housing is positioned such that the first stage of theplurality of stages is out of the magnetic field and the second stage ofthe plurality of stages is within the magnetic field.
 8. The heat pumpof claim 7, wherein the regenerator housing is movable relative to themagnet assembly.
 9. The heat pump of claim 7, further comprising a motorin mechanical communication with the one of the regenerator housing orthe magnet assembly and configured for moving the one of the regeneratorhousing or the magnet assembly along the longitudinal direction.
 10. Theheat pump of claim 9 wherein the motor is in mechanical communicationwith the regenerator housing.
 11. A heat pump system, comprising: a coldside heat exchanger configured for heat removal from a first localenvironment; a hot side heat exchanger configured for heat delivery to asecond local environment; a first pump for circulating a working fluidbetween the cold side heat exchanger and the hot side heat exchanger; asecond pump for circulating a working fluid between the cold side heatexchanger and the hot side heat exchanger; and a heat pump in fluidcommunication with the cold side heat exchanger, the hot side heatexchanger, the first pump and the second pump, the heat pump comprising:a magnet assembly, the magnet assembly comprising a first magnet and asecond magnet, the first magnet and the second magnet spaced apart alonga vertical direction such that a gap is defined between the first magnetand the second magnet and a magnetic field is created in the gap; aregenerator housing, the regenerator housing comprising a body defininga plurality of chambers, each of the plurality of chambers extendingalong a transverse direction orthogonal to the vertical direction; aplurality of stages, each of the plurality of stages comprising amagnetocaloric material disposed within one of the plurality of chambersand extending along the transverse direction between a first end and asecond end; and a support frame, the support frame comprising an upperframe member and a lower frame member spaced apart along the verticaldirection from the upper frame member, the support frame furthercomprising an adjustable intermediate member disposed between the upperframe member and the lower frame member, wherein the first magnet isconnected to the upper frame member and the second magnet is connectedto the lower frame member, and wherein adjustment of the adjustableintermediate member adjusts a length of the gap.
 12. The heat pumpsystem of claim 11, wherein the magnet assembly is a plurality of magnetassemblies, wherein each of the first magnets is connected to the upperframe member and each of the second magnets is connected to the lowerframe member.
 13. The heat pump system of claim 11, wherein theadjustable intermediate member is a screw jack.
 14. The heat pump systemof claim 11, further the adjustable intermediate member is formed from amagnetically shielding material.
 15. The heat pump system of claim 11,wherein the support frame defines an interior space and an exteriorspace, the interior space and the exterior space disposed on opposingsides of the magnet assembly along the longitudinal direction.
 16. Theheat pump system of claim 11, wherein the support frame comprises aC-shaped portion.
 17. The heat pump system of claim 11, wherein one ofthe regenerator housing or the magnet assembly is movable relative tothe other of the regenerator housing or the magnet assembly along alongitudinal direction orthogonal to the vertical direction and thetransverse direction, and wherein in a first position along thelongitudinal direction the regenerator housing is positioned such that afirst stage of the plurality of stages is within the magnetic field anda second stage of the plurality of stages is out of the magnetic field,and wherein in a second position along the longitudinal direction theregenerator housing is positioned such that the first stage of theplurality of stages is out of the magnetic field and the second stage ofthe plurality of stages is within the magnetic field.
 18. The heat pumpsystem of claim 17, wherein the regenerator housing is movable relativeto the magnet assembly.
 19. The heat pump system of claim 17, furthercomprising a motor in mechanical communication with the one of theregenerator housing or the magnet assembly and configured for moving theone of the regenerator housing or the magnet assembly along thelongitudinal direction.
 20. The heat pump system of claim 19, whereinthe motor is in mechanical communication with the regenerator housing.